The technology of the present disclosure relates to an image forming apparatus.
In general, a fixing device mounted in an electrophotographic image forming apparatus is provided with a temperature detection sensor for detecting the surface temperature of a heating roller. As a detection system of the temperature detection sensor, two kinds of a contact type and a non-contact type have been known. In the contact type temperature detection sensor, a thermistor is made contact with the surface of the heating roller to detect the surface temperature of the roller. Therefore, the surface of the heating roller may be damaged by the thermistor. On the other hand, in the non-contact type temperature detection sensor, since the sensor needs not to be made to directly contact with the heating roller, the surface of the heating roller is not damaged. However, in the non-contact type temperature detection sensor, there is a problem that dust such as toner and paper dust is attached to a temperature detection surface and detection accuracy is reduced.
In order to solve such a problem, a technology of performing fluorine coating on the surface of the temperature detection surface has been proposed. In this way, although contamination has been attached to the temperature detection surface of the temperature detection sensor for example, it is possible to remove the contamination by simple cleaning work.
Furthermore, an image forming apparatus configured such that the temperature detection sensor is covered by a box-like cover member has been proposed. The air in the cover member is sucked by a suction fan. In this way, since the pressure in the cover member becomes a positive pressure (higher than the atmospheric pressure), it is possible to prevent dust from being attached to the temperature detection sensor.